BRAND NAME(S): Ontak

WARNING: Unlikely but very serious (possibly fatal) side effects may occur during treatment with denileukin diftitox. Tell your doctor immediately if you have any unusual symptoms during the infusion (see Side Effects section). Also tell your doctor immediately if you experience any of the following symptoms: dizziness, lightheadedness, fainting, sudden weight gain, swelling ankles/feet, or vision changes (e.g., loss of vision/color vision).